I am new to javascript.
I have coded a basic app in JS to allow a user to type a message into a prompt.
I want to display the message on the page.
From there, the user can click one of three buttons to change the text colour.

My questions are, how can I allow them to change the font and size of the text and allow the text to scroll?


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Untitled Document</title>
<script>
function red(){
document.fgColor='red'
}
//end of function "yellow()"

function blue(){
document.fgColor='lightblue'
}
//end of function "blue()"

function green(){
document.fgColor='lightgreen'
}
//end of function "green()"

//This "user-defined" function allows the user to click a button before being
//prompted to type a message in a box.
//Then the javascript asks the user to confirm the message, they type ok and
//the document.write function display the message in a new window.

function message(usermsg){

x=(usermsg);
document.write (""+x);

}


</script>

</head>

<body>
<script language="javascript1.2">
var usermsg = prompt ("Enter a message no longer than 200 characters", "");
message (usermsg);

</script>


<form>
<input type="button"
value="red"
onclick="red()">

<input type="button"
value="blue"
onclick="blue()">

<input type="button"
value="green"
onclick="green()">
</form>

</body>
</html>